1800 Thomas Earnshaw was a pioneer in marine timekeeping. This pocket chronometre has a plain steel balance and bimetalic 'sugar tongs' to compensate for changing temperatures. The watch was owned by Charles George Perceval, 2nd Baron Arden, Lord of the Admiralty. Thomas Earnshaw, London Fusee, spring detent escapement ,balance with spring, temperature compensation (P&E CAI-1731)
aperture=f4.5 focal length: 60.0 mm exposure 1/200 sec ISO: 3200